Pump



July 13 1955 R. M. VAN HOUSE 3,194,484

PUMP

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67 Haber? 272 Van/30u56 1a* BY 5 Y 'il .4M fg/mf 6i 60 als AroR/viy July 13, 1965 R. M. VAN HOUSE 3,194,484

PUMP

Filed March 1a, 196s 2 Sheets-Sheet 2 United States Patent O Delaware Filed Mar. 18, 1963, Ser. No. 265,700 2 Claims. (Cl. 23d- 52) The invention relates to a pump of the vacuum operated type, and more particularly to one in which two power compartments are provided on opposite sides of a power wall and two pistons are received in compression cylinders and attached to a common piston rod driven by the power wall. Features of the invention include the particular mechanism for controlling and actuating the valve for alternately supplying vacuum and atmospheric air to the power compartments to drive the power wall and to replenish air in the compressing cylinders to be compressed by the pistons. echanism embodying the invention provides a simple and effective valve control arrangement operating in timed relation to the movement of the pump power wall and piston rod assembly which quickly reverses the connections of vacuum and atmospheric air to the power chambers to provide a minimum power loss in each operating stroke.

The mechanism includes a rack and gear arrangement with a lost motion drive to an overcenter action valve controlling mechanism which reverses the vacuum and atmosphere connections to the pump power compartments in timed relation to movement of the pump pistons.

In the drawings:

FIGURE 1 is a cross section View of a pump mechanism embodying the invention.

FIGURE 2 is a section view of the mechanism taken in the direction of arrows 2 2 of FIGURE 1.

FIGURE 3 is a partial section view of the valve portion of the mechanism taken in the direction of arrows 3 3 of FIGURE 2.

FIGURE 4 is a partial section view of the mechanism taken in the direction of arrows 4 4 of FIGURE 2.

FIGURE 5 is a partial section view of the mechanism taken in the direction of arrows 5 5 of FIGURE 2.

FIGURE 6 is a partial section view of the mechanism generally similar to FIGURE 3 but showing the valve mechanism in the other port communication position.

FIGURE 7 is a detail view of a portion of the valve contained in the mechanism of FIGURE l and showing the valve face.

The pump housing 10 has a power wall 12 illustrated as a diaphragm which divides the housing into power chambers 14 and 16. A piston rod assembly 18 is secured to and through the diaphragm 12 and extends through the power chambers 14 and 16. Compression pistons 2t) and 22 are provided at either end of assembly 1S. The pistons are respectively received for reciprocation within cylinders 24 and 26 formed in the housing 10 and respectively connecting with the chambers 14 and 16. Cylinders 2.4 and 26 cooperate with pistons 20 and Z2 to dene compression chambers 28 and 30. Each compression chamber is provided at its outer end with a check valve 32 which when open connects the associated compression chamber with the air pressure outlets 34 and 36. Each check valve 32 has a valve closing spring 38 which urges the valve closed and must be overcome by the compression of air in the associated compression chamber to open the valve against the force of the spring and deliver the compressed air to the compressed air outlet. Piston rod assembly 18 also includes a gear rack 4? which is illustrated as being formed of annular lands and grooves about the section of the piston rod between ice the power wall and one of the pistons. Reciprocating movement of the piston rod under force exerted on the power wall by differential pressures in chambers 14 and 16 actuates the valve operating mechanism in a timed relation which controls the admission of vacuum and atmospheric air to the power chambers.

Housing 16 is provided with three ports 44, 46 and 48. Port 44 is connected through vacuum supply passage 56 to a suitable source of vacuum. Ports 46 and 48 are arranged generally on opposite sides of port 44 and respectively connect with chambers 14 and 16. A sliding valve 52 has a cavity 54 formed in the face thereof engaging the housing surface through which three ports extend. Cavity S4 is always connected with port 44 and connects either port 46 or port 48 with port 44, depending upon the valve position. The port not connected with port 44 is open to atmosphere. Thus one of the power chambers has vacuum applied to it and the other has atmoshperic air applied to it, depending upon the position of valve 52. The two valve positions are shown in FIGURES 3 and 6.

A valve carrier 56 is rotatably mounted on a rotatable shaft 58 which is suitably mounted in housing lil so that one end of the shaft extends into chamber 16 and the other end extends out of the housing and into the interior of the valve cover 60. Carrier 56 receives valve 52 therein and holds the valve in such a position that it moves arcuately upon pivotal movement of the carrier to alternate between the two port communication positions. A valve spring 62 is provided to hold the valve against the face of the housing so that it can seal the three ports to the desired operating extent while remaining slidable on the housing. An arm 64 extends radially from the valve end of shaft 58 and has a pad 65 on the outer portion thereof which contacts one of the sides of the valve cover 60 during its operation as shaft 58 is arcuately reciprocated in the manner to be described. An overcenter spring 66 is attached to arm 64 and to an arm 68 formed as a part of valve carrier 56. Arms 64 and 68 are so arranged that pivotal movement of the arm 64 will pass the spring 66 over the axis of shaft 58 and the spring tension will then move the valve carrier with a snap action. Stops 7@ and 72 are provided on either side of the Valve cover 66 so that opposite sides of the carrier 56 are alternately engaged with these stops to precisely position the valve 52 in one of the two port communication positions. Arm 64 extends through an angularly formed slot 74 formed in valve carrier 56 so that the valve carrier is free to move about shaft 58 under influence of the overcenter spring 66.

The end of the shaft 58 extending into chamber 16 has a gear 76 rotatably mounted about it and aligned for engagement with the rack 46 so that the gear is r0- tated about the axis of shaft 58 when rack 40 is reciprocated. The extreme end of shaft 58 is provided with a slot 78 extending diametrically therethrough. Gear 76 is provided with an angular slot 8i) which is in alignment with one end of the slot 78. A gear and shaft cap 82 has a key 84 integrally formed therewith so that the key extends into slots 78 and 8l) as shown in FIGURES 1, 2 and 5. The cap ts over a hub end of gear 76 in a free sealing relationship. It is held tightly on the end of shaft 58 and does not interfere with the gear and rack. Suitable washers 86 and 88 are provided about shaft 58 adjacent housing 10 against which the gear '76 and the valve carrier 56 respectively are received.

In the position shown in FIGURE 1, the leftward movement of the diaphragm has rotated the gear 76 by means of rack 46 until one side of the slot 80 in the gear has engaged the key 7S and has rotated the key to also rotate the shaft 58. This movement of shaft 58 and gear 76 is counterclockwise as seen in FIGURE 5, resulting in clockwise movement of shaft 58 and arm 64 as seen in FIGURE 3, from the valve positionshown in FIGURE 6. ThisA causesthe overcenter spring 66 to move over the axis fof shaft 58 and cause counterclock- Wise rotation of the valve carrier 56 from the position shown in FIGURE 6 to the position shown in FlGURE 3. This changes the port communication position ofthe valve 52 from the position wherein port 46, and therefore chamber I4, was connected to vacuum, with port 48 connected to atmosphere, to the position where port 48, and therefore chamber 16, is connected to vacuum and port 46 is Connected to atmosphere to provide atmospheric air in chamber 14. The differential pressure act- Y ing on diaphragm 12 then moves the diaphragm and the piston and rod assembly 18 to the right as seen in FIG- URE 1. This movement rotates gear 76 yclockwise as seen in FIGURE but doesnot initially move shaft 58 since key 84 is in the angular slot Si) and the gear must move relative to the -key until the other side of the slot 3h engages thekey. When this occurs, continued rotation of gear 76 moves key 84 which then rotates shaft 58 clockwise as seen in FIGURE 5, and counterclockwise as seen in FIGURE 3. This causes arm 6d to move counterclockwise as seen in FIGURE 3, again passing overcenter spring 66 over the axis of shaft 53 and causing a snap vaction movement of the valve carrier 56 to position the valve carrier in the position shown in FIG- URE 6. This again reverses the atmospheric and vacuum pressures in chambers 14 and 16, causingthe diaphragrn 12 to move back to the left as seen in FIGURE l. The cycle is repeated to obtain the double piston pumping action.

Charging of the compression chambers 28 and St) is obtained by means of the flexible valves 9) and 92 and the piston passages 94 and 96 respectively formed through the pistons 2t) and 22. When the power wall and piston rod assembly are moving to the left as seen in FIGURE 1, air is being compressed in chamber 28 and iiexible valve 90 closes passages 94. At the same time, atmospheric air in chamber 16 passes through passages 96 of pistonV 22 and flexible valve 92 opens to permit the airv to charge chamber 30. The check valve at the end of chamber 30 is closed at this time. Reverse movement of the pistons causes ilexible valve 92 to close passages 96 so that air is compressed in chamber 30, and flexible valve 90 to open passages 94 so that a charge of airis transmitted to chamber 28. n

In the claims:

1. In a pump, in combination, a housing formed with two chambers, a reciprocable piston rod in said chambers, said housing being formed with a pair of ports for establishing communication between the chambers and the' atmosphere and a third port adapted for connection to a source of vacuum, a valve carrier having a valve received therein and operatively pivotally mounted on said housing, said valve being arranged to selectively establish communication of the third port with either ot the other ports while uncovering the remaining port to the do atmosphere upon pivotal movement ot said carrier, stop means on said housing for selectively limiting carrier pivotal movement in opposite directions to selectively establish the position of the valve in either of said port communication positions, an overcenter crankshaft rotatably received in said housing and rotatably receiving said valve carrier thereon at one end and having a crank arm extending therefrom adjacent said carrier, an overcenter spring attached to said arm and said carrier and selectively'holding said'carrier against said stop means in said port communication positions, a rack on said piston rod and a gear rotatably mounted on the other end of said shaft and engaging saidrack to be driven thereby, and Vlost motion connection means between said lshaft and said gear for rotating said shaft with said gear when said piston rod is adjacent each stroke end to actuate said carrier. t' Y 2. A vacuum operated pump comprising a housing having a power wall dividing said housing into a pair of actuation compartments, irst and second cylinders respectively formed in said housing and connecting with said actuating compartments, a piston rod h'avingtpistcns formed on the opposite'ends thereof reciprocably received in saidvcompartments and said cylinders'and secured tok said power wall for actuation thereby, valve means in each of said pistons for recharging said cylinders when Ythe pressure in each of said cylinders is respectively less than the pressure in the power compartment connected therewith, rst and second ports in said housing for establishing communication between the power cornpartments and the atmosphere and a third port adapted for connection to a source of vacuum, a rotatable shaft received in said housing and having one end extending into one of said actuation compartments and the other end thereof being positioned adjacent said ports, valve means rotatably mounted on said rotatable Vshaft to selectively establish communication'of said third port with either of said lirst and second ports While uncovering the remaining port to the atmosphere, snap action overcenter means connecting said shaft and said valve means for selectively positioning said valve means, and means actuated by said piston rod near the opposite stroke limits thereof and including a rack on said piston 4rod and a gear rotatable on said shaft and lost motion connection means between sai-d gear and said shaft.

n References Cited by the Examiner UNITED STATES PATENTS 407,338 7/89 Downie.

862,867 S/07 Eggleston a 230-52 1,747,921 2/30 Abels 91-*351 X 1,766,010 6/30 Binderup.

` 2,630,102 3/53 Osburn V 230-52 f FOREIGN PATENTS 583,249 12/ 46 Great Britain.

LAURENCE V. EFNER, Examiner.V 

1. IN A PUMP, IN COMBINATION, A HOUSING FORMED WITH TWO CHAMBERS, A RECIPROCABLE PISTON ROD IN SAID CHAMBERS, SAID HOUSING BEING FORMED WITH A PAIR OF PORTS FOR ESTABLISHING COMMUNICATION BETWEEN THE CHAMBERS AND THE ATMOSPHERE AND A THIRD PORT ADAPTED FOR CONNECTION TO A SOURCE OF VACUUM, A VALVE CARRIER HAVING A VALVE RECEIVED THEREIN AND OPERAIVELY PIVOTALLY MOUNTED ON SAID HOUSING, SAID VALVE BEING ARRANGED TO SELECTIVELY ESTABLISH COMMUNICATION OF THE THIRD PORT WIH EITHER OF THE OTHER PORTS WHILE UNCOVERING THE REMAINING PORT TO THE ATMOSPHERE UPON PIVOTAL MOVEMENT OF SAID CARRIER, STOP MEANS ON SAID HOUSING FOR SELECTIVELY LIMITING CARRIER PIVOTAL MOVEMENT IN OPPOSITE DIRECTIONS TO SELECTIVELY ESTABLISH THE POSITION OF THE VALVE IN EITHER OF SAID PORT COMMUNICATION POSITIONS, AN OVERCENTER CRANKSHAFT ROTATABLY RECEIVED IN SAID HOUSING AND ROTATABLY RECEIVING SAID VALVE CARRIER THEREON AT ONE END AND A HAVING A CRANK ARM EXTENDING THEREFROM ADJACENT SAID CARRIER, AN OVERCENTER SPRING ATTACHED TO SAID ARM AND SAID CARRIER AND SELECTIVELY HOLDING SAID CARRIER AGAINST SAID STOP MEANS IN SAID PORT COMMUNICATION POSITINS, A RACK ON SAID PISTON ROD AND GEAR ROTAABLY MOUNTEDON THE OTHER END OF SAID SHAFT AND ENGAGING SAID RACK TO BE DRIVEN THEREBY, AND LOST MOTION CONNECTION MEANS BETWEEN SAID SHAFT AND SAID GEAR FOR ROTATING SAID SHAFT WITH SAID GEAR WHEN SAID PISTON ROD IS ADJACENT EACH STROKE END TO ACTUATE SAID CARRIER. 